1. Field of the Invention
The present invention relates generally to methods of sealing and sealing devices and particularly for methods and devices for sealing between and around connections between a control device and fluid passages within a housing.
2. Description of Related art
It is sometimes desireable to install a flow control device into an installation bore which intercepts and communicates with one or more fluid passage contained within a housing, requiring provision for fluid communication between the intercepted fluid passage and the ports of the flow control device while sealing against internal or external leakage and to prevent cross over of flow. Conventional methods of sealing of such devices utilize "O" rings or other elastomeric seal materials, an example of which is illustrated in FIG. 9. Such seals are typically retained within a groove and may in miniature applications, be cumbersome causing disproportionately large distances between ports. Moreover, such conventional seals are fully expanded upon assembly on the member to be sealed and therefore, to provide substantial radial sealing force, the seals must have an outside diameter greater than the inside diameter of the installation bore, thereby crating an interference fit. Such seals must be formed of substances that are both deformable and sufficiently elastic to exert adequate sealing force and many suitable materials are relatively soft and are readily damaged by the interference with the installation hole as well as any burrs caused by the interception o creation of fluid passage ways in the side wall of the installation hole. Avoiding damage to the seal by resorting to a stepped installation hole increases the complexity and the size of the overall installation. Moreover, the radial Clearance between the installation bore and the body of the installed device may only be bridged by the elastomeric seal material, which, being relatively soft may not withstand exposure to high pressure fluids. Such sealing devices only provide sealing between axially separated ports, thereby presenting limitations in the number of separate ports that can be accommodated within a limited axial dimension.